Usability and bug fixes

Added some nice start up text/headers and included an input line at the
end of the program to keep it open even after termination.

While loop added to continue dongle connection attempts.

Removed (possibly unnecessary) program wait before receiving the
response from the ECU. If the ECU sends the data back quickly it will
miss the first few characters it sends. the wait is probably not needed
here. Further debugging needed.